1. Field of the Invention
The present invention relates to a gasket material and particularly to a gasket material excellent in durability against refrigerating machine oil, Freon gas, antifreeze liquid, etc.
2. Description of the Related Art
Generally, a gasket mounted on a compressor for a refrigerating machine in an automobile, or a gasket mounted on an engine has a structure in which a rubber layer are laminated with using a primer on a steel plate. The two steps of forming a primer layer and forming the rubber layer are however required. Therefore, a gasket material using no primer has been developed. For example, JP-A-11-1678 has described a gasket material having a structure in which a film made of a mixture of an unvulcanized rubber compound and a phenolic resin or epoxy resin is directly formed on a steel plate.
In the gasket material using no primer, it is necessary to mix a considerably large amount of the phenolic resin or epoxy resin with the unvulcanized rubber compound in order to obtain sufficient adhesion between the mixture film and the steel plate. As a result, there is brought a disadvantage in that elasticity of the mixture film is lowered so that sealability is lowered.